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pganguet avatar image
pganguet asked

Split phase on a single multiplus II

So RV application in USA. Since it has a large battery I use the RV as backup for my 120/240v house during power outages. I must have 240v. Using a MP2 I can get 240v and use a transformer to derive a neutral and have my split phase out. But when I'm traveling, I can encounter both 120v only or 120/240v input connections. Obviously the MP2 wont accept 120v. Any way anyone can think to be able to use one transformer to derive a neutral on both input and output? I don't want the weight and standby losses of two transformers. I drew this up thinking it might work but I'm hoping for a better solution:

split phase
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1 Answer
Johannes Boonstra (Victron Energy Staff) avatar image
Johannes Boonstra (Victron Energy Staff) answered ·

Hi, first on losses, of course the transformer can create a loss, but this is powered from the grid line (which wouldn't effect you much) and also only when there is an unbalance. So taking 240Vac from 2 x 120Vac means there are no losses. The schematic you made does unfortunate not work ( and is quite dangerous as you forward the N to/from grid without switching!). the only option you would have is to install a AT on both input and output i am afraid.( and keep them isolated from each other!)

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